Process of treating zinc-bearing ore.



is To all whom z't may concern:

UN IT134111 STATES AT KQE,

JAMES o. Jormsronn, or BUFFALO, NEW YORK.

PROCESS OF TREATING ZINC-BEARING- ORE.

1,029,932. No Drawing.

. 'Beit known that 1, JAMES OhJonnsronn, a subject of Great Britain, residing 1n Buffalo, in the county of Erie and State of Neva York, have invented new and useful Improvements in Processes'of Treating Zinc- Bearing Ore, of which the following is a specification.

This invention relates to a process for the treatment of ores containing a mixture-of barites and zinc mineral, and has for its object to separate the barites from the sine, and to recover the zinc as zinc sulfidm a simple and economical manner. 15

T e process consists, briefly, in reducing the barites (barium sulfate to barium sulfid, and then by leaching'dissolving the barium compounds and leaving the zinc content to be recovered as zinc sulfid.

The reduction of the barites may be ef-- fected by heating the mixed ore to a red heat, or hotter, in the presence of carbon or carbonaceous matter, such as charcoal, coal,- ligni'te, saw-dust, etc., or in the presonce of producer gas, natural gas, or any fuel gas or oil, or sulfur vapor, sulfureted hydrogemearbon disulfid vapor; orby a mixture of any 'or all of these reducing agents. The reduction occurs according to the following equation:

Another way of removing the barium carbonate would be by heating the material in a current of steam whereby the barium' earbonate changed to hydroxid, and then leaching out the barium hydroxid with hot Water.

"Specification of Letters Patent.

Application filed July 20, 1911. Serial No. 639,474.

. hours.

scale in the following manner: The ore containing the zinc and. barites is first crushed to 16 or 20 mesh and concentrated to remove lime, silica, etc. One hundred pounds of cleaned ore (wet or dry) is next' mixed intimately. with twenty pounds of powdered charcoal. The mixture is then charged into the zinc retort which is sealed, ,except for a smallopening to let the carbonic oxid esc'ape. It is then heated for three hours. The mixture is next taken from the retort as rapidly as possible and put in an; iron receptacle which should then be covered so as'to prevent combustion. It is difllcul't to prevent combustion to some extent when operating on this small scale duringthe trans for from the retort to the receptacle. When fairly cool the mixture is crushed to about Patented June 18, 1912.

The'process may be carried out one small 6 or 10 mesh, but must not be pulverized.

The crushed material is then charged into a leaching vat, and boiling water is run into the vat slowly, so as to use-not more' than about one-half of a gallon of water per minute. If the water should flow faster than this the exit from the vat may be I plugged to reduce the rate of flow. The level of water in the vat should be kept above the level of the solid. .The pouring in of the hot water should continue until about fifty gallons has been usedfor until the filtrate shows only a little precipitate with a solution of sodium carbonate. This operation should take from two to four The first twenty or twenty-fivegaL lons of filtrate should be received in a separate wooden receptacle, such as afbarrel,

from the remainder, and should show crystals of barium sulfid when 0001, In prac-' tice the second half of the wash water-would be used to leach afresh portion of roasted ore; in this way it also would become 'saturated and yield crystals on cooling, and so there would be economy in the use of hot water. If the mass in the vat should cake when the water is first added, due to cooling and crystallization, it may be necessary to break it up with a rod. If, however, the water flows at all it need not be disturbed for subsequent portions of hot water will loosen it. \Vhen the leaching has been completed the residue may be again placed in the retort for a second treatm nt. More charcoal may have to be added if the fir ,t

portion seems to have been all used up. t is heated in the retort for from two and nehalf to three hours, then transferred to the iron receptacle, cooled, crushed to mesh and placed in the leaching vat as before. It is then leached with about twenty gallons of hot water'and allowed to drain thorou'ghly. The next step consists in ouring over the mass about ten gallons of ourteen per cent. acetic acid solution. This is .obtained by mixing five gallons of commercial twenty-eight er cent. acid with an equal solution of l ioiling water. The filtrate is received in a wooden tub or barrel, and ispassed through a second time. If it passedthrough very slowly the.first time, the second treatment may be omitted. The ore is finally washed by pouring over it about two gallons of water. To regenerate the acetic acid it is necessary to know by analysis the amount of barium it has taken into solution. Then by adding the exact amount of sulfuric acid to precipitate the barium .as insoluble sulfate, the

barimf'p acetic acid is regenerated an ready for the The barium sulfate after next treatment. filtering and washing is ready for the market as blanc fixe.

If the leached product is sufiiciently high grade withclit vthe acid treatment the latter may be omitted.

I claim p 1. The process of treating ores containing "zinc and barites which consists in heating the orein the presence of a reducing agent which converts the barium sulfate to barium sulfid, and :subse uently leaching the mixture whereby the arium sulfid will 0 into solution and leave insoluble zinc sul d.

i 2. The process of treating ores containing zinc and barites which consists in heating the ore in the presence of a carbonaceous reducinga ent which converts the barium sulfate to arium sulfid, and subsequently leaching the mixture whereby the barium sulfid Will go into solutionand leave insoluble zinc sulfid.

'3.' The process of treating ores containing a mixture of zinc and barites which consists in reducing the barium sulfate to barium sulfid by heating the mixture in the presence of a reduclng agent and subsequently leaching .the mixture, whereby the barium compounds are dissolved and the zinc com pounds 'a re'left as insoluble sulfids.

at. The'processof treating ores containing a -mixture of zinc and barites which consists 1 h heating the mixed" ore to a red heat, or hotter, in the prose nee of a reducing agent which convertsthe barium sulfate to barium sulfid, and subsequently leaching the mixture with water whereby the barium sulfid goes into solution andthe zinc content may be recovered in the form of insoluble zinc sulfid. e

,5. The, process of treating ore. containing a mixture of zinc and barltes which" consists in heating themixture in the presence of areducing agent which converts the barium sulfate to bariumsulfid, then leaching the mixture, whereby the barium sulfid goes into solution, and then removing any ba.-

rium carbonate present in the original ore; or produced during the treatment by dissolvin' it in a dilute acid." I

6. T e processof treating ore contain ng a mixture of Z1110 and barites which conslsts in heating the mixture in the presence ofa carbonaceous reducing agent which converts,

the barium sulfate to barium sulfid, then leaching the mixture, whereb the barium sulfid goes into solution, and t en removing any barium carbonate present in the original ore or produced during the treatment by dissolving it in a dilute acid.

7. The-process of-treating ore containing a mixture of zinc and barites; which consists in heating the ore in the presence of a re ducing agent which converts the barium sulfate to barium sulfid subsequently leaching the mixture, where y the barium sulfid goes into solution, then pouring-dilute acid over the ore to recover any barium carbonate, and then adding sulfuric acid to the so lfntion to precipitate insoluble barium sulate.

' 8. The process of treating ore containing a mixture of -21nc and barites which consists in heating the ore in the presence of a reducing agent which converts the barium sulfate to barium sulfid, subsequently leaching the product, whereby the barium sulfid goes into solution and leaves insoluble zinc sulfids, then again heating the residue, and again leaching the same.

9. The process of treating-ore containing a mixture of zinc and barli tes which consists in heating the ore in the presence of a reduc' ing agent which converts the barium sulfate to barium sulfid, subsequently leaching the product, whereby the barium sulfid goes into solution and leaves insoluble zinc sulfids,

then again heating the residue, and again leaching the same, and 'finally subjecting said zinc residue to the action of a weak acid to remove any barium carbonate.

In testimony whereof, I have hereunto set my hand in presence of two subscribing witnesses.

JAMES, o. JoHNs'roNEf Witnesses:

J orm L. GAnnnTsoN, GEO. D. Owens. 

